Sony Dream Machine ICF-C121

WHoever sells the transformer should know!!!!!!

Well, I couldn't tell you exactly except for, I bet they are rated for half of what was put into it! :)

And, what the hell is a Dream Machine? Sounds a little kinky!

"

Contact Sony and ask them who their parts distributor is for your area. Also find out who does their authorised service in your area.

In the worse case you will have to put in the original transformer. Then you get an external transformer that can step down the 220 VAC to

120 VAC for your unit. Make sure that the wattage rating of the step down is at least a minimum of 40% to 60% greater than the wattage rating of the unit that it is going to be connected to.

For the step down, just make sure you get a proper transformer and not one of these small low cost electronic thrystor types. The electronic type of step down will damage the transformer in your unit.

Jerry G.

--

On Sep 9, 8:52=A0pm, Ardent  wrote:
> Hi Friends
>
> Someone plugged my Dream machine (rated 110 VAC) into a 220 VAC outlet
> and the transformer primary got trashed. Since I will be living here
> for a while I thought of getting a transformer made here locally (very
> cheap, honest).
>
> There are two independent secondaries and will thank anyone who can
> tell me what the outputs are.
>
> --
> Thanks for your time and attention
>
> Ardent

The primary of the transformer being trashed, might very well be the least of your worries. Power transformers are pretty robust, and it is likely that the primary survived for at least some tens of miliseconds before failing, and possibly more than that. This means that for this period, the secondary voltages will have been double their nominal value, which could have done rather more serious downstream damage ...

Sorry to throw this one in, but it's a problem that we see fairly regularly in the UK with visitors from the US, and often they think it is just going to be a simple power problem like a fuse, and it turns out to be rather more serious. You might be one of the lucky ones and have gotten away with it. Let's hope :-)

Arfa

These are not transformers. They're more like a lamp dimmer.

The person rebuilding the transformer (should it come to that) might be able to rewind for 220V.

Hi!

It's an alarm clock sold by Sony. There's nothing special about it--most of them are just AM/FM radios with a digital clock built in.

Oh, and some of them call the snooze button a "dream bar".

William

Well, thanks to all of you for responding, though I got no useful information. I said I am in a 220 VAC area so I thought of getting a new 220 VAC transformer made to avoid using a step down transformer at the same time eliminate the accident repeat in future.

I can always get a spare (110 VAC one) when I return home.

--
Thanks for your time

Ardent

I'm willing to bet it's rather more than just the transformer. Copper takes time to melt while solid state destructs near instantly.

--
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    Dave Plowman        dave@davenoise.co.uk           London SW
                  To e-mail, change noise into sound.

You are ignoring core saturation. That limits the maximum voltage on the secondary. I have replaced several 120 VAC transformers that opened when plugged into 240 VAC and had no problems with the electronics. You aren't always lucky, but if it is a typical cheap as possible transformer it will die first.

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Agreed. The fact the transformer was damaged -- which likely doesn't occur instantly -- suggests that at least a few parts in the power supply let out their life-giving smoke.

But wouldn't that require enough current draw to saturate? Or are you arguing that the transformer is so cheap that it normally operates close to saturation, anyway?

I see small transformers like this fry very quickly with double voltage applied. Happens all the time here in the US when the neutral lifts. Most often that is all that is wrong, though I'll admit that does sound surprising.

Mark Z.

Most cheap consumer items that I've looked at are so close to saturation that their transformers start to saturate & overheat at less than 20% over the rated voltage. I have seen some with less than a 10% margin. Even worse, the cheap bastards didn't use a thermal fuse in the core or metal bells for fire protection, and set the plastic cases on fire. I had to locate & replace hundreds of substandard transformers a service center installed in some old Jerrold/ General Instruments JRX3/JSX3 Cable TV boxes. Luckily, the rest of their work was just as shoddy, and all but a half dozen were back in the shop before they caught fire out of over 8000 that were in service.

It isn't hard to test for saturation. A variac, a low voltage lamp that is close to the primary current, and a scope across the secondary. Slowly bring the input voltage up, until the output starts to flat top, and read the input voltage. The lamp will light, or burn out if you turn it too high, to protect both transformers. It was part of the process to qualify a new transformer for our products. It also helped catch a bad vendor who changed the design, do save them a little money after the design was accepted.

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There are two kinds of people on this earth:
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I reckon you've been lucky then Michael. Living here in a 240v country, I see several pieces of kit a year that have either come over from the states with their owners to live here, or have been brought back here by UK holiday makers, picking up that 'deal of the century' at Walmart. Almost always, although agreed not *always* always, in my experience, the damage which ensues from plugging these 120v transformer based items into 240v line power, is not limited to just the transformer primary winding failing.

However, I have seen more than a few which have had a perfectly conventional glass fuse in the primary, which has failed violently, but has managed to protect both the transformer, and the following circuitry ...

Arfa

You may be have to figure out the voltages by looking at the circuit that are being powered. Power supply cap voltages will give you a maximum, and IC data sheets should also help. Have you done an autopsy on the old transformer? Sometimes the primary opens like a fuse near one end where it's soldered to the wires.

It's unlikely that Sony will sell parts, or even a service manual for something as inexpensive as a clock radio. I also doubt you will be able to buy a replacement transformer for less than the cost of a new radio. It's fine if you want to do this for the challenge, but it won't be a money saving venture. Andy Cuffe

snipped-for-privacy@gmail.com

You also have the problem of 50 Hz, vs 60 Hz, which requires a larger core, and makes it easier to saturate a transformer made for the North America markets. If the primary is impedance limited, it allows the core to heat quite a bit before the primary winding opens. If the DC supply is close to the upper limit on the semiconductors, or electrolytics, it does a lot of damage before it opens. That was why we tested a lot of parameters on iron core transformers.

It was even worse when we moved to SMPS. We went through a dozen suppliers before we found one that met our EMI requirements. the rest either radiated too much noise, or had noise on the DC rails, and it was within one of the IF frequencies. All SMPS had to be tested for over current shutdown, and even then we had one fail in a radio during burn in. It didn't shut down, and it destroyed a new $20,000 radio a customer was waiting for.

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The first sign of insanity is denying that you\'re crazy.

Of course they will. But this radio is old enough (I assume) that Sony no longer stocks parts for it. The manual is probably still available, but it's likely you'll pay a lot for a photocopy.

Businesses (in general) seem to be increasingly less worried about breaking the laws that require them to stock service parts.

The service manual is online at

for 6 Euro's ...

--
Adrian C

In the UK it's common to get long warranties on quite low price things - a

3 year one on a 20 quid cordless drill. But they don't repair them if they go wrong - just give you a like for like replacement or your money back. Perhaps that's why such things cost about twice as much as in the US. ;-)

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    Dave Plowman        dave@davenoise.co.uk           London SW
                  To e-mail, change noise into sound.